Gel electrolyte lithium-ion battery containing ionic polymer and method of manufacture

Abstract

The present invention relates to the field of lithium ion batteries, and more particularly to a gel electrolyte lithium ion battery containing an ionic polymer and a manufacturing method thereof. The gel electrolyte lithium ion battery containing the ionic polymer of the present invention comprises a positive electrode, a negative electrode, a separator, and an electrolyte, wherein at least one of the positive electrode, the negative electrode, or the separator comprises an ionic polymer, and M in the ionic polymer w / M a is 2 to 2000, where M w is the weight average molecular weight of the ionic polymer, M a is the ratio of the mass of the ionic polymer to the number of moles of anionic groups contained therein, and the above M a The gel electrolyte lithium-ion battery utilizes the conventional production process, and can avoid the problems of the prior art, such as the complicated process caused by adding a gel polymer or its precursor to the electrolyte, or the instability of the electrolyte and difficulty in permeating the electrodes, and can meet the demand for high energy density batteries.

Description

Related Applications

[0001] This application claims priority to a prior application filed in China on February 13, 2023, with application number 202310158789.2, the entire contents of which are incorporated herein by reference. [Technical Field]

[0002] The present invention relates to the field of lithium ion batteries, specifically to a gel electrolyte lithium ion battery containing an ionic polymer and a method for manufacturing the same. [Background technology]

[0003] The advantages of using gel electrolytes instead of conventional liquid electrolytes in lithium-ion batteries are that it prevents leakage of the electrolyte and reduces the evaporation of the electrolyte solvent, thereby improving safety, and that it reduces contact between the electrolyte and the surface of the active material, thereby suppressing decomposition of the electrolyte, improving the battery's high-temperature performance, extending battery life, and contributing to improved safety.

[0004] There are two methods for using gel electrolytes in lithium-ion batteries: one is commercialized by Sony, where a crystalline polymer, typically a copolymer of vinylidene fluoride and hexafluoropropylene P (VDF-co-HFP), is added to an electrolyte precursor to form a viscous liquid, which is then applied to the electrode strips. The low-boiling point solvent in the electrolyte precursor is then extracted, forming a gel in which the polymer and electrolyte are physically crosslinked. Another is commercialized by Samsung, where a precursor containing a monomer or oligomer with multiple double bond functional groups, typically a variety of monomers or oligomers containing acrylate or methacrylate groups, is added to the electrolyte along with an initiator. The electrolyte is then injected into a dry cell, and the double bonds are polymerized by heating or UV irradiation, converting the electrolyte into a chemically crosslinked gel, a process known as in-situ curing.

[0005] Of the above technologies, the first technology has very few polymer options, with the only successful example being PVDF copolymer, adopted by Sony. However, this technology has two major drawbacks: the complex process results in high costs; and the gel electrolyte essentially does not contain low-boiling-point solvents, resulting in low electrolyte conductivity, limiting the rate and low-temperature performance of the battery. The second technology has a relatively large selection of monomers or oligomers, but it also has two major drawbacks: the electrolyte is prone to gelation, meaning it can only be stored at low temperatures for a short period of time; and the high viscosity of electrolytes containing monomers or oligomers makes it difficult for the electrolyte to fully penetrate the voids in the electrode, meaning it cannot meet the demand for high-energy density batteries with low-porosity electrodes. Summary of the Invention

[0006] The problems that the invention aims to solve are as follows: the manufacturing process of gel electrolyte lithium ion batteries in the prior art is complicated, the electrolyte is unstable, and it is difficult to sufficiently infiltrate the electrodes, which results in high manufacturing costs and makes it impossible to meet the production requirements of high energy density batteries.

[0007] To solve the above problems, the present application provides the following technical solutions. The present application relates to a gel electrolyte lithium ion battery containing an ionic polymer, the battery comprising a positive electrode, a negative electrode, a separator, and an electrolyte, wherein at least one of the positive electrode, the negative electrode, or the separator contains an ionic polymer, and M in the ionic polymer. w / M a is 2 to 2000, where M w is the weight average molecular weight of the ionic polymer, M a is the ratio of the mass of the ionic polymer to the number of moles of anionic groups contained therein, and M a The present invention provides a gel electrolyte lithium-ion battery having a molecular weight of 100 to 2000 g / mol.

[0008] In some embodiments of the present application, M in the ionic polymer w / M ais 2 to 1000, preferably 2 to 500. In some embodiments of the present application, the M a is 100 to 1000 g / mol. In some embodiments of the present application, the swelling degree of the ionic polymer in the electrolyte solution is greater than 50% at 25 to 60°C, preferably the swelling loss rate of the ionic polymer in the electrolyte solution is <5%, and more preferably the swelling degree is 50 to 500%.

[0009] In some embodiments of the present application, the positive electrode includes a current collector and a positive electrode material applied to the current collector, preferably the positive electrode material includes a positive electrode active material and an ionic polymer, more preferably the content of the ionic polymer is 1 to 10% with respect to the total weight of the solid content of the positive electrode material, and / or the negative electrode includes a current collector and a negative electrode material applied to the current collector, preferably the negative electrode material includes a negative electrode active material and an ionic polymer, more preferably the content of the ionic polymer is 1 to 10% with respect to the total weight of the solid content of the negative electrode material; And / or, the separator includes a polymer microporous layer and a separator coating material applied to the polymer microporous layer, and preferably the separator coating material includes inorganic particles and an ionic polymer, and more preferably the content of the ionic polymer is 1 to 80% based on the total weight of the solid content of the separator coating material.

[0010] In some embodiments of the present application, the anionic group of the ionic polymer is one or more selected from the group consisting of carboxylate ions, sulfonate ions, sulfate ions, and phosphate ions, and preferably, the cation of the ionic polymer is one or more selected from the group consisting of lithium ions, sodium ions, magnesium ions, calcium ions, barium ions, and aluminum ions.

[0011] In some embodiments of the present application, the ionic polymer is one or more polymers selected from polyethers containing at least two anionic groups, polyesters containing at least two anionic groups, polyolefins containing at least two anionic groups, polycarbonates containing at least two anionic groups, and polyamides containing at least two anionic groups.

[0012] In some embodiments of the present application, the ionic polymer is one or more polymers selected from the following formulas 1 to 7.

[0013] [ka]

[0014] wherein R1 to R3 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X1 to X3 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group; and at least one of X1 to X3 is an ionic group containing an anion group and a cation; and m and n are both integers of 1 to 5,000.

[0015] [ka]

[0016] wherein R4 to R6 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X4 to X6 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group; and at least one of X4 to X6 is an ionic group containing an anion group and a cation; and m and n are both integers of 1 to 5,000.

[0017] [ka]

[0018] Here, R7~R 11 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, and a sulfur-containing substituted hydrocarbon group; 10 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group, and X7 to X 10 At least one of the groups is an ionic group containing an anionic group and a cation, and n is an integer of 1 to 5,000.

[0019] [ka]

[0020] where R 12 ~R 17 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X 11 ~X 14are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group, and X 11 ~X 14 At least one of the groups is an ionic group containing an anionic group and a cation, and l, m, and n are all integers of 1 to 5,000.

[0021] [ka]

[0022] where R 18 ~R 20 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X 15 ~X 17 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group, and X 15 ~X 17 At least one of the groups is an ionic group containing an anionic group and a cation, and m and n are both integers of 1 to 5,000.

[0023] [ka]

[0024] where R 21 ~R 23 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X 18 ~X 20 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group, and X18 ~X 20 At least one of the groups is an ionic group containing an anionic group and a cation, and m and n are integers of 1 to 5,000.

[0025] [ka]

[0026] where R 24 ~R 28 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X 21 ~X 25 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group, and X 21 ~X 25 At least one of the groups is an ionic group containing an anionic group and a cation, and n is an integer of 1 to 5,000.

[0027] In some embodiments of the present application, the polyolefin containing at least two anionic groups in the polymer side chain is formed by copolymerization of an olefinic monomer containing an ionic group and an olefinic monomer not containing an ionic group, and the structural formula of the olefinic monomer containing an ionic group is as shown below:

[0028] [ka]

[0029] wherein R1, R2, and R3 are each independently selected from a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, an oxygen-containing substituted hydrocarbon group, or a halogen-containing substituted hydrocarbon group; R4 is selected from a hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, an oxygen-containing substituted hydrocarbon group, or a halogen-containing substituted hydrocarbon group; and X is an ionic group including an anionic group and a cation.

[0030] In some embodiments of the present application, the olefinic monomer not containing an ionic group includes one or more of styrene, methylstyrene, acrylonitrile, acrylate, methacrylate, acrylamide, N-substituted methacrylamide, vinyl ether, N-vinylpyrrolidone, vinylpyridine, maleic anhydride, maleimide, vinylene carbonate, or vinylethylene carbonate.

[0031] In some embodiments of the present application, the electrolytic solution contains an organic solvent and a lithium salt. Preferably, the organic solvent is one or more selected from ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, and methyl propyl carbonate. More preferably, the lithium salt is one or more selected from lithium hexafluorophosphate, lithium tetrafluoroborate, lithium di(trifluoromethylsulfonyl)imide, and lithium bisfluorosulfonylimide, and preferably lithium hexafluorophosphate.

[0032] In some embodiments of the present application, the electrolytic solution further contains one or more of an unsaturated cyclic carbonate, a fluorinated cyclic carbonate, a cyclic sultone, and a cyclic sulfate. Preferably, the unsaturated cyclic carbonate is selected from vinylene carbonate and / or vinylethylene carbonate, and / or the fluorinated cyclic carbonate is at least one selected from fluoroethylene carbonate, trifluoromethylethylene carbonate, and bisfluoroethylene carbonate, and / or the cyclic sultone is at least one selected from 1,3-propane sultone, 1,4-butane sultone, and propenyl-1,3-sultone, and / or the cyclic sulfate is at least one selected from vinyl sulfate, propylene sulfate, and 4-methylvinyl sulfate.

[0033] The present invention further provides a method for manufacturing the above-mentioned gel electrolyte lithium ion battery, the method including the steps of forming a positive electrode, a negative electrode, and a separator into a battery cell, placing the battery cell in a battery case, then injecting an electrolyte solution to obtain a semi-finished lithium ion battery, forming the semi-finished lithium ion battery, venting the battery, and sealing the liquid inlet of the battery case to obtain a gel electrolyte lithium ion battery.

[0034] The present invention includes a current collector and an electrode material coating applied to the current collector, wherein the electrode material coating is M w / M a The active material and ionic polymer have a molecular weight of 2 to 2000, wherein M w is the weight average molecular weight of the ionic polymer, M a is the ratio of the mass of the ionic polymer to the number of moles of anionic groups contained therein, and the above M a is 100 to 2000 g / mol, preferably the amount of the ionic polymer added is 1 to 10% based on the total weight of the solid content of the electrode material, and more preferably the electrode is a positive electrode or a negative electrode.

[0035] The present invention includes a polymeric microporous layer and a separator coating material applied to the polymeric microporous layer, wherein the separator coating material includes an ionic polymer, inorganic particles, and an adhesive, and the M in the ionic polymer is w / M a is 2 to 2000, where M w is the weight average molecular weight of the ionic polymer, M a is the ratio of the mass of the ionic polymer to the number of moles of anionic groups contained therein, and the above M a is 100-2000 g / mol, preferably the dosage of the ionic polymer is 1-80% based on the total weight of the solid content of the separator coating material, more preferably the polymer microporous layer is a polyolefin microporous film or nonwoven fabric.

[0036] Beneficial effects of the present invention: (1) The present invention is w / M a An ionic polymer having a molecular weight of 2 to 2000 is added to a positive electrode, a negative electrode, or a separator. After contacting the ionic polymer with an electrolyte, the ionic polymer absorbs the electrolyte and swells to form a gel electrolyte. This allows the use of conventional production processes, reduces the complexity of the manufacturing process, and reduces the cost of production equipment. This avoids the problems of conventional technologies, such as the complicated process caused by adding a gel polymer or its precursor to the electrolyte, or the instability of the electrolyte and its difficulty in infiltrating into the electrodes, and meets the demand for high energy density batteries.

[0037] (2) The ionic polymer used in the present invention is a polymer containing two or more anionic groups, and the ratio of the mass of the ionic polymer to the number of moles of the anionic groups contained therein is 100 to 2000 g / mol. By controlling the swelling degree of the ionic polymer in the electrolyte solution within an appropriate range, the gel electrolyte has good electrical conductivity and fully exhibits the effects of the gel electrolyte, while the polymer does not swell excessively in the electrolyte solution or dissolve and lose its function. DETAILED DESCRIPTION OF THE INVENTION

[0038] In order to clarify the purpose, technical solutions and technical effects of the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. The embodiments described below are only some of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, those skilled in the art can easily obtain all other embodiments without any creative effort, and all other embodiments will fall within the scope of the present invention.

[0039] In order to better understand the above technical solution, the present invention will be further described in detail below. The present invention adds an ionic polymer to a positive electrode, a negative electrode, or a separator, and after contacting the ionic polymer with an electrolyte, it absorbs the electrolyte and swells to form a gel electrolyte. This reuses the conventional production process and avoids the problems of the prior art, which are caused by adding a gel polymer or its precursor to the electrolyte, such as a complicated process or an unstable electrolyte that is difficult to infiltrate into the electrodes. The ionic groups contained in the ionic polymer are advantageous for improving the electrical conductivity of ions and for forming a gel formed by physical cross-linking. In addition to exhibiting the various beneficial effects of the gel electrolyte described above, this is also advantageous for providing a gel electrolyte battery with a high energy density and excellent charge / discharge cycle performance.

[0040] In a specific embodiment of the present invention, the present invention provides a gel electrolyte lithium ion battery comprising an ionic polymer, the battery comprising a positive electrode, a negative electrode, a separator, and an electrolyte, wherein at least one of the positive electrode, the negative electrode, or the separator comprises an ionic polymer, and M in the ionic polymer w / M a is 2 to 2000, where M w is the weight average molecular weight of the ionic polymer, M a is the ratio of the mass of the ionic polymer to the number of moles of anionic groups contained therein, and the above M a The present invention provides a gel electrolyte lithium-ion battery having a molecular weight of 100 to 2000 g / mol.

[0041] It should be understood that M in ionic polymers w / M a is 2 to 2000 indicates that the ionic polymer molecular structure contains an average of 2 to 2000 anionic groups. In some embodiments of the present invention, the ionic polymer w / M a is 2 to 1000, preferably 2 to 500.

[0042] The ionic polymer can form a physically crosslinked structure by aggregating ionic groups, and controlling the content of anionic groups within the appropriate range not only ensures that the formed gel electrolyte has good ionic conductivity, but also prevents the gel electrolyte from excessively swelling in the electrolyte or dissolving and losing its function. That is, if the ionic polymer contains too many ionic groups, the swelling degree may be too low to form a gel, and if the content is too low, the gel electrolyte may swell excessively or dissolve.

[0043] In some embodiments of the present invention, in the ionic polymer, M w / M a may be 2 to 2000, 2 to 1500, 2 to 1100, 2 to 1000, 2 to 900, 2 to 800, 2 to 700, 2 to 500, 2 to 200, 2 to 150, 2 to 140, 2 to 130, 2 to 120, 2 to 110, 3 to 2000, 5 to 2000, 10 to 2000, 15 to 2000, 20 to 2000, or 100 to 2000. In some embodiments of the present invention, in the ionic polymer, M w / M a is 2.0, 2.02, 2.03, 2.06, 3.0, 3.9, 5.0, 10.0, 11.97, 14.74, 15, 19.97, 20, 85.23, 100, 102.93, 104.23, 110, 120, 130, 140, 150, 200, 500, 700, 800, 900, 1000, 1004.96, 1500, or 2000, or within a numerical range having any two of the above specific values ​​as endpoints. w / M a It should be understood that in a specific embodiment, any of the above ranges can be combined with any other range, so long as a gel electrolyte lithium ion battery having the properties required by the present invention is obtained.

[0044] In some embodiments of the present invention, the M a is 100 to 1000 g / mol. The mass of the ionic polymer and the number of moles of anionic groups contained in it (Ma If the ratio of the mass of the ionic polymer to the number of moles of anionic groups contained therein is less than 100 g / mol, the content of ionic groups will be too high, there will be too many physical cross-linking points, and the swelling degree of the polymer in the electrolyte will be too small, reducing the electrical conductivity of the formed gel electrolyte. On the other hand, if the ratio of the mass of the ionic polymer to the number of moles of anionic groups contained therein is more than 2000 g / mol, the content of ionic groups will be too low, and the polymer will swell excessively in the electrolyte or dissolve and lose its function.

[0045] In some embodiments of the present invention, in the ionic polymer, M a is 100~2000g / mol, 150~2000g / mol, 200~2000g / mol, 250~2000g / mol, 300~2000g / m ol, 350~2000g / mol, 400~2000g / mol, 450~2000g / mol, 500~2000g / mol, 550~2000g / m ol, 600~2000g / mol, 650~2000g / mol, 700~2000g / mol, 750~2000g / mol, 800~2000g / mol, 850~2000g / mol, 900~2000g / mol, 950~2000g / mol, 1000~2000g / mol, 100~1950g / mol, 100 to 1900 g / mol, 100 to 1850 g / mol, 100 to 1800 g / mol, 100 to 1750 g / mol, 100 to 1700 g / mol, 100 to 1650 g / mol, 100 to 1600 g / mol, 100 to 1550 g / mol, 100 to 1500 g / mol, 100 to 1450 g / mol, 100 to 1400 g / mol, 100 to 1350 g / mol, 100 to 1300 g / mol, 100 to 1250 g / mol, 100 to 1200 g / mol, 100 to 1150 g / mol, 100 to 1100 g / mol, 100 to 1050 g / mol, or 100 to 1000 g / mol. aare 100g / mol, 142g / mol, 150g / mol, 155g / mol, 200g / mol, 237g / mol, 250g / mol, 281g / mol, 294g / mol, 300g / mol, 350g / mol, 362g / mol, 386g / mol, 400g / mol, 4 50g / mol, 500g / mol, 504g / mol, 550g / mol, 590g / mol, 600g / mol, 625g / mol, 650g / mol, 700g / mol, 750g / mol, 800g / mol, 850g / mol, 900g / mol, 950g / mol, 1000 g / mol, 1050 g / mol, 1100 g / mol, 1125 g / mol, 1140 g / mol, 1150 g / mol, 1200 g / mol, 1250 g / mol, 1300 g / mol, 1350 g / mol, 1400 g / mol, 1450 g / mol, 1500 g / mol, 1550 g / mol, 1600 g / mol, 1650 g / mol, 1700 g / mol, 1750 g / mol, 1800 g / mol, 1850 g / mol, 1900 g / mol, 1950 g / mol, or 2000 g / mol, or a range of values ​​between any two of the above specific values. a It should be understood that in a specific embodiment, any of the above ranges can be combined with any other range so long as a gel electrolyte lithium ion battery having the properties required by the present invention is obtained.

[0046] In some embodiments of the present invention, the ionic polymer has a swelling degree of more than 50% in the electrolyte at 25 to 60°C, preferably a swelling loss rate of <5%, more preferably a swelling degree of 50 to 500%, even more preferably a swelling degree of 50 to 300%, and even more preferably a swelling degree of 100 to 200%. If the swelling degree is less than 50%, the electrical conductivity of the gel electrolyte formed by the polymer is very low, and the internal resistance of the battery increases, affecting the battery's charge / discharge rate performance and low-temperature cycle performance. If the swelling degree is more than 500%, the mechanical performance of the ionic polymer decreases or it dissolves in the electrolyte, losing its function as a gel electrolyte.

[0047] It should be noted that the molecular weight of the ionic polymers described in this invention is the absolute molecular weight of the ionic polymers measured by gel permeation chromatography-laser light scattering (GPC-MALLS). The ratio of the mass of the ionic polymer described in the present invention to the number of moles of anionic groups contained therein (M a ) was measured using an inductively coupled plasma optical emission spectrometer (ICP-OES) to determine the concentration of metal cations in the ionic polymer, and the ratio (g / mol) of the mass of the ionic polymer to the number of moles of anionic groups contained therein was calculated using the formula:

[0048]

number

[0049] In the above formula, C i is the concentration of metal cations in the polymer measured by ICP-OES, in g / kg, and M i is the relative atomic mass of the corresponding metal cation, and n i is the valence of the metal cation, e.g., Li + and Na + So n i is 1 and Mg 2+ and Ca 2+ Then the corresponding n i is 2 and Al 3+ Then the corresponding n i is 3.

[0050] The swelling degree described in this invention refers to the ratio of the difference in mass of ionic polymer before and after immersion in electrolyte to the mass of the polymer before immersion.Specific test method is to prepare ionic polymer into a circular film sheet with a thickness of 30 μm and a size of 16 mm × 16 mm, weigh the film sheet, immerse the film sheet in 10 g of electrolyte, seal and store at a certain temperature, take out the film sheet every 8 hours, wipe off the electrolyte on the surface, measure the thickness, weigh, return to the electrolyte, seal and continue to store at the same temperature, continue to test three times until the thickness and mass of the film sheet remain unchanged, in which case it is considered that the ionic polymer film sheet has reached a swelling equilibrium state. Calculate the swelling degree according to the following formula:

[0051]

number

[0052] In the above formula, m0 represents the mass of the ionic polymer film sheet before immersion in the electrolyte, and m1 represents the mass of the ionic polymer film sheet when it reaches swelling equilibrium after immersion in the electrolyte.

[0053] The swelling loss rate described in this invention refers to the ratio of the mass loss due to the dissolution of a portion of the polymer in the electrolyte when the ionic polymer swells in the electrolyte to the mass of the polymer before swelling. The specific test method is as follows: the ionic polymer is cut into a circular film sheet with a thickness of 30 μm and a size of 16 mm × 16 mm. The film sheet is weighed, immersed in 10 g of electrolyte, sealed, and stored at 60 ° C. Every 8 hours, the film sheet is removed, the electrolyte on the surface is wiped off, the thickness is measured, the weight is measured, the film is returned to the electrolyte, sealed, and stored at 60 ° C. This is continued until the thickness and mass of the film sheet remain unchanged after three consecutive tests. The film sheet is then immersed in dimethyl carbonate (DMC) to remove the electrolyte from the film sheet, and then placed in a drying box to dry completely. The mass of the remaining film sheet after drying is weighed, and the swelling loss rate is calculated according to the following formula:

[0054]

number

[0055] In the above formula, m0 represents the mass of the ionic polymer film sheet before immersion in the electrolyte solution, and its unit is g, and m2 represents the mass of the ionic polymer film sheet remaining after immersion in the electrolyte solution, further washing, and drying, and its unit is g.

[0056] In some embodiments of the present invention, the ionic group includes an anionic group and a cation, and the anionic group is one or more selected from carboxylate ions, sulfonate ions, sulfate ions, and phosphate ions. Preferably, the cation of the ionic group is one or more selected from lithium ions, sodium ions, magnesium ions, calcium ions, barium ions, and aluminum ions. Polymers containing carboxylate ions, sulfonate ions, sulfate ions, and phosphate ions are easy to prepare and stable in air. In particular, the carboxylate ions, sulfonate ions, sulfate ions, and phosphate ions have relatively tight bonds with cations such as lithium ions, and can form physical crosslinks with the cations without dissolving in the electrolyte. The cation may be one or more selected from lithium ions, sodium ions, magnesium ions, calcium ions, barium ions, and aluminum ions. In particular, the cation may be lithium ions (Li + ), the lithium ions are partially dissociated in the electrolyte, which is advantageous for improving the electrical conductivity of the lithium ions in the gel electrolyte, and the cation is Na + When the cation is Mg, it does not contribute to the electrical conductivity of lithium ions, but it does not adversely affect the performance of lithium ion batteries. 2+ and Ca 2+ divalent ions such as Al 3+ In the case of a trivalent ion such as , it can bond with two or three anions and is difficult to dissociate in the electrolyte, which is more advantageous for forming physical crosslinking points and does not adversely affect the performance of the lithium ion battery.

[0057] In some embodiments of the present invention, the anionic groups are bonded to the end groups or side chains of the ionic polymer, i.e., the anionic groups are bonded to the ionic polymer chains by chemical bonds; in this way, the anionic groups are not mobile in an electric field, which is advantageous for improving the mobility of lithium ions in the formed gel electrolyte.

[0058] The ionic polymer of the present invention is one or more selected from polyethers, polyesters, polyolefins, polycarbonates, and polyamides. It should be noted that polyethers, polyesters, polyolefins, polycarbonates, and polyamides are mainly classified based on differences in their main chain structures. For example, the structural formula of a polyether includes, but is not limited to, Formula 1; the structural formula of a polyester includes, but is not limited to, Formula 2 or Formula 3; the structural formula of a polyolefin includes, but is not limited to, Formula 4; the structural formula of a polycarbonate includes, but is not limited to, Formula 5; and the structural formula of a polyamide includes, but is not limited to, Formula 6 or Formula 7.

[0059] [ka]

[0060] wherein R1 to R3 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X1 to X3 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group; and at least one of X1 to X3 is an ionic group containing an anion group and a cation; and m and n are both integers of 1 to 5,000.

[0061] [ka]

[0062] wherein R4 to R6 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X4 to X6 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group; and at least one of X4 to X6 is an ionic group containing an anion group and a cation; and m and n are both integers of 1 to 5,000.

[0063] [ka]

[0064] Here, R7~R 11 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, and a sulfur-containing substituted hydrocarbon group; 10 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group, and X7 to X 10 At least one of the groups is an ionic group containing an anionic group and a cation, and n is an integer of 1 to 5,000.

[0065] [ka]

[0066] where R 12 ~R 17 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X 11 ~X 14are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group, and X 11 ~X 14 At least one of the groups is an ionic group containing an anionic group and a cation, and l, m, and n are all integers of 1 to 5,000.

[0067] [ka]

[0068] where R 18 ~R 20 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X 15 ~X 17 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group, and X 15 ~X 17 At least one of the groups is an ionic group containing an anionic group and a cation, and m and n are both integers of 1 to 5,000.

[0069] [ka]

[0070] where R 21 ~R 23 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X 18 ~X 20 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group, and X18 ~X 20 At least one of the groups is an ionic group containing an anionic group and a cation, and m and n are both integers of 1 to 5,000.

[0071] [ka]

[0072] where R 24 ~R 28 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X 21 ~X 25 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group, and X 21 ~X 25 At least one of the groups is an ionic group containing an anionic group and a cation, and n is an integer of 1 to 5,000.

[0073] According to the present invention, ionic polymers of polyether, polyester, polycarbonate, or polyamide containing two or more anions in their terminal groups are usually synthesized by modifying the terminal groups. The most typical synthetic route is to first synthesize a polyether having a hydroxyl or carboxyl terminal group, a polyester having a hydroxyl or carboxyl terminal group, a polycarbonate having a hydroxyl terminal group, or a polyamide having an amino or carboxyl terminal group, and then convert the terminal group to the desired ionic group.

[0074] For example, a typical synthetic route to polyether-based ionic polymers can be divided into two steps. Step 1 is to obtain a polyether polyol by initiating ring-opening polymerization of an epoxy monomer from a polyol. Typical polyols include ethylene glycol, glycerin, trihydroxymethylpropane, and pentaerythritol, and typical epoxy monomers include ethylene oxide, propylene oxide, 1,3-dioxolane, and 1,4-dioxane.

[0075] Step 2 is to replace the hydroxy groups of the polyether polyol with ionic groups, a typical reaction being, for example, as follows:

[0076] [ka]

[0077] For example, polyester-based ionic polymers can be divided into two types: the main chain is obtained by initiating the ring-opening polymerization of lactone-based monomers from polyols, and the typical synthetic route is similarly divided into two steps.

[0078] Step 1 is to obtain polyester polyol by initiating ring-opening polymerization of lactone monomers from polyol. Typical polyols include ethylene glycol, glycerin, trihydroxymethylpropane, and pentaerythritol, and typical lactone monomers include lactide, δ-valerolactone, and ε-caprolactone.

[0079] Step 2 is to replace the hydroxy group of polyester polyol with an ionic group, and the synthesis reaction is the same as the method described in Step 2 of the synthesis of polyether-based ionic polymer.

[0080] The other main chain is obtained by polycondensation of diacid monomers and diol monomers, and its synthesis can be divided into two steps.

[0081] Step 1 is to obtain a polyester polyol by polycondensation of a diacid monomer and a diol monomer. Typical diacids include succinic acid and adipic acid, and typical diols include ethylene glycol, 1,3-propanediol, and 1,6-hexanediol.

[0082] Step 2 is to replace the hydroxy group of polyester polyol with an ionic group, and the synthesis reaction is the same as the method described in Step 2 of the synthesis of polyether-based ionic polymer.

[0083] The synthesis of polycarbonate-based ionic polymers can also be divided into two steps.

[0084] Step 1 is to obtain a polycarbonate polyol by initiating ring-opening polymerization of a cyclic carbonate monomer from a polyol, and typical polyols include ethylene glycol, glycerin, trihydroxymethylpropane, pentaerythritol, etc., and typical cyclic carbonate monomers include ethylene carbonate, propylene carbonate, etc.

[0085] Step 2 is to replace the hydroxy group of polyester polyol with an ionic group, and the synthesis reaction is the same as the method described in Step 2 of the synthesis of polyether-based ionic polymer.

[0086] In addition, a desired ionic group-containing polymer can be obtained by polymerizing a monomer that itself contains an ionic group. A typical example involves polycondensation of an ionic group-containing dibasic acid represented by the following formula with a diol or diamine to obtain the corresponding ionic group-containing polyester or polyamide:

[0087] [ka]

[0088] Here, R1 and R2 are each independently selected from a hydrocarbylidene group, a halogenated hydrocarbylidene group, an oxygen-containing substituted hydrocarbylidene group, a nitrogen-containing substituted hydrocarbylidene group, a phosphorus-containing substituted hydrocarbylidene group, and a sulfur-containing substituted hydrocarbylidene group, X1 and X2 are ionic groups containing the above anionic group and cation, and n is an integer of 1 to 5000. The number of carbon atoms in the hydrocarbon group is not particularly limited as long as it satisfies the requirements for application of the present invention.

[0089] According to the present invention, the synthesis route of polyolefin-based ionic polymers containing two or more anions in the polymer side chain is to copolymerize an olefin-based monomer containing an ionic group with an olefin-based monomer not containing an ionic group under the action of an initiator, and the structural formula of the olefin-based monomer containing an ionic group is as follows:

[0090] [ka]

[0091] wherein R1, R2, and R3 are each independently selected from a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, an oxygen-containing substituted hydrocarbon group, or a halogen-containing substituted hydrocarbon group; R4 is selected from a hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, an oxygen-containing substituted hydrocarbon group, or a halogen-containing substituted hydrocarbon group; and X is an ionic group including an anionic group and a cation.

[0092] The olefinic monomer not containing an ionic group includes one or more of styrene, methylstyrene, acrylonitrile, acrylate, methacrylate, acrylamide, N-substituted methacrylamide, vinyl ether, N-vinylpyrrolidone, vinylpyridine, maleic anhydride, maleimide, vinylene carbonate, and vinylethylene carbonate.

[0093] According to the present invention, the ionic polymer includes, but is not limited to, one or more polymers selected from the following:

[0094] [ka]

[0095] [ka]

[0096] According to the present invention, the positive electrode includes one or more of polyester 1, polyester 2, polyolefin 2, polyolefin 3, polycarbonate 1, polycarbonate 2, and polyamide 1, but is not limited thereto; and / or the negative electrode comprises, but is not limited to, one or more of polyether 1, polyether 5, polyolefin 1, polyamide 2, and polyamide 3; and / or the separator includes, but is not limited to, one or more of Polyether 2, Polyether 3, Polyether 6, Polyolefin 1, and Polyolefin 4. According to the present invention, the positive electrode material contains, relative to the total weight of the solid content of the positive electrode material, one or more of 0-2% polyester 1, 0-1% polyester 2, 0-3% polyolefin 2, 0-3% polyolefin 3, 0-10% polycarbonate 1, 0-5% polycarbonate 2, and 0-2.5% polyamide 1, but is not limited thereto; and / or the negative electrode material includes, but is not limited to, one or more of 0-4% polyether 1, 0-8% polyether 5, 0-10% polyolefin 1, 0-4% polyamide 2, and 0-5% polyamide 3, based on the total weight of the solid content of the negative electrode material; And / or, the separator coating material contains, relative to the total weight of the solid content of the separator coating material, one or more of 0 to 20% polyether 2, 0 to 8% polyether 3, 0 to 80% polyether 6, 0 to 80% polyolefin 4, and 0 to 60% polyolefin 1, but is not limited thereto, and preferably the separator coating material contains one or more of 4 to 20% polyether 2, 0 to 8% polyether 3, 1 to 80% polyether 6, 1 to 80% polyolefin 4, and 0 to 60% polyolefin 1.

[0097] In some embodiments of the present invention, the electrolyte solution contains an organic solvent and a lithium salt. Preferably, the organic solvent is one or more selected from ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, and methyl propyl carbonate, and is preferably ethylene carbonate and / or ethyl methyl carbonate. More preferably, the volume ratio of ethylene carbonate to ethyl methyl carbonate is 2 to 4:6 to 8. Even more preferably, the lithium salt is one or more selected from lithium hexafluorophosphate, lithium tetrafluoroborate, lithium di(trifluoromethylsulfonyl)imide, and lithium bisfluorosulfonylimide, and is preferably lithium hexafluorophosphate. More preferably, the concentration of lithium hexafluorophosphate in terms of volume of the electrolyte solution is 1 to 2 mol / L.

[0098] In some embodiments of the present invention, the electrolyte solution further contains one or more of an unsaturated cyclic carbonate, a fluorinated cyclic carbonate, a cyclic sultone, and a cyclic sulfate. Preferably, the unsaturated cyclic carbonate is selected from vinylene carbonate and / or vinylethylene carbonate, and / or the fluorinated cyclic carbonate is at least one selected from fluoroethylene carbonate, trifluoromethylethylene carbonate, and bisfluoroethylene carbonate, and / or the cyclic sultone is at least one selected from 1,3-propane sultone, 1,4-butane sultone, and propenyl-1,3-sultone, and / or the cyclic sulfate is selected from vinyl sulfate and / or 4-methylvinyl sulfate. More preferably, the electrolyte solution contains 1 to 2% vinylene carbonate and 0.5 to 1.5% 1,3-propane sultone by weight.

[0099] In some embodiments of the present invention, the positive electrode includes a current collector and a positive electrode material coated on the current collector. The current collector may be any of various current collectors known to those skilled in the art, such as aluminum foil, carbon-coated aluminum foil, or aluminum-plated polymer film. The positive electrode material includes the ionic polymer and a positive electrode active material, and the content of the ionic polymer is 1 to 10% based on the total weight of the solid content of the positive electrode material. It should be understood that the positive electrode material further includes a positive electrode conductive agent and an adhesive, and the positive electrode active material is lithium nickel cobalt manganese oxide (LiNi x Co y Mn 1-x-yThe positive electrode conductive agent may include, but is not limited to, one or more of a carbon black conductive agent, carbon nanotubes (CNT), SP-Li, flake graphite, Ketjen black, VGCF, and CNF. The adhesive may include, but is not limited to, one or more of polyvinylidene fluoride (PVDF), a homopolymer and a copolymer of vinylidene fluoride (VF2), and a copolymer of vinylidene fluoride (VF2) and hexafluoropropylene (HFP).

[0100] In some embodiments of the present invention, the negative electrode includes a current collector and a negative electrode material coated on the current collector. The current collector may be any current collector known to those skilled in the art, such as copper foil, carbon-coated copper foil, or copper-plated polymer film. The negative electrode material includes the ionic polymer and a negative electrode active material, with the ionic polymer content ranging from 1 to 10% based on the total weight of the solid content of the negative electrode material. It should be understood that the negative electrode material further includes a negative electrode conductive agent and an adhesive. The negative electrode active material includes, but is not limited to, artificial graphite (C) or mesocarbon microbeads. The conductive agent includes, but is not limited to, one or more of carbon black conductive agent, carbon nanotubes (CNT), SP-Li, conductive graphite, flake graphite, Ketjen black, VGCF, and CNF. The adhesive includes, but is not limited to, one or more of styrene butadiene rubber latex (SBR), sodium carboxymethyl cellulose (CMC), and polyacrylic acid polymer (PAA).

[0101] In some embodiments of the present invention, the separator includes a microporous polymer layer and a separator coating material applied to the microporous polymer layer, the separator coating material including the ionic polymer and inorganic particles, and the content of the ionic polymer is 1 to 80% based on the total weight of the solid content of the separator coating material. It should be understood that the separator coating material further includes an adhesive, the adhesive including, but not limited to, one or more of polyvinylidene fluoride (PVDF), styrene butadiene rubber latex (SBR), and sodium carboxymethyl cellulose (CMC), and the inorganic particles including, but not limited to, at least one of ceramic powder, alumina, boehmite, calcium carbonate, hydrotalcite, montmorillonite, spinel, titania, silica, zirconia, magnesium oxide, calcium oxide, beryllium oxide, magnesium hydroxide, calcium hydroxide, and silicon carbide.

[0102] It should be noted that the solid content of the positive electrode material, the solid content of the negative electrode material, or the solid content of the separator coating material used as the basis for the above content refers to the solid components other than the solvent in the positive electrode material, negative electrode material, or separator coating.

[0103] In some embodiments of the present invention, the method for producing the positive electrode includes mixing the positive electrode materials to obtain a slurry, applying the slurry to the current collector, and then drying the slurry to obtain a lithium-ion battery positive electrode.

[0104] In some embodiments of the present invention, the method for producing the negative electrode includes mixing the negative electrode materials to obtain a slurry, applying the slurry to the current collector, and then drying the slurry to obtain a lithium-ion battery negative electrode.

[0105] In some embodiments of the present invention, the method for manufacturing the separator includes mixing the separator coating material to form a slurry, applying the slurry to the polymer microporous layer, and then drying to obtain a lithium ion battery separator.

[0106] The present invention includes a current collector and an electrode material applied to the current collector, wherein the electrode material is M w / M a The ionic polymer, active material, conductive agent and adhesive have a molecular weight of 2 to 2000, w is the weight average molecular weight of the ionic polymer, M a is the ratio of the mass of the ionic polymer to the number of moles of anionic groups contained therein, and the above M a The present invention further provides a lithium ion battery electrode having a ionic polymer content of 100 to 2000 g / mol. Preferably, the amount of the ionic polymer added is 1 to 10% based on the total weight of the solid content of the electrode material.

[0107] It should be understood that the above electrode includes a positive electrode or a negative electrode, and when the electrode is a positive electrode, the electrode material refers to a positive electrode material and the active material refers to a positive electrode active material, and when the electrode is a negative electrode, the electrode material refers to a negative electrode material and the active material refers to a negative electrode active material.

[0108] The present invention includes a polymeric microporous layer and a separator coating material applied to the polymeric microporous layer, wherein the separator coating material is w / M a The composition includes an ionic polymer, inorganic particles, and a pressure-sensitive adhesive, wherein M w is the weight average molecular weight of the ionic polymer, M a is the ratio of the mass of the ionic polymer to the number of moles of anionic groups contained therein, and the above M a The present invention further provides a lithium ion battery separator having a ionic polymer content of 100 to 2000 g / mol. Preferably, the amount of the ionic polymer added is 1 to 80% based on the total weight of the solid content of the separator coating material.

[0109] The present invention further provides a method for manufacturing the above-mentioned lithium ion battery, comprising the steps of forming a positive electrode, a negative electrode, and a separator into a battery cell, placing the battery cell in a battery case, then injecting an electrolyte solution to obtain a semi-finished lithium ion battery, forming the semi-finished lithium ion battery, and evacuating the battery, and then sealing the liquid inlet of the battery case to obtain a lithium ion battery, wherein at least one of the positive electrode, the negative electrode, and the separator comprises the above-mentioned ionic polymer.

[0110] The present invention will be further described below with reference to examples. It should be understood that these examples are for illustrative purposes only and do not limit the scope of the present invention.

[0111] The raw materials and reagents used in the present invention were all purchased from mainstream manufacturers in the market. Those without a specified manufacturer or concentration are all routinely available analytically pure grade raw materials and reagents, and are not particularly limited as long as they achieve the desired effect. The equipment used in the examples was all purchased from major manufacturers in the market, and is not particularly limited as long as they achieve the desired effect. Unless specific techniques or conditions are specified in the examples, they are carried out in accordance with the techniques or conditions described in the literature in the field or in accordance with the product instructions.

[0112] Reagents: Oxalic acid, ethylene glycol, p-toluenesulfonic acid, LiOH, azobisisobutyronitrile, dibenzoyl peroxide, stannous octanoate, acrylonitrile, methyl acrylate, vinyl sulfonic acid, methacrylic acid, polyethylene glycol methyl ether methacrylate, 2-acrylamido-2-methylpropanesulfonic acid, 2-hydroxyethyl methacrylate phosphate, 1,3-propanesultone, propylene carbonate monomer, N,N-dimethylformamide, polyethylene glycol PEG 400, polyethylene glycol The following substances are sourced from Shanghai McKinley Biochemical Technology Co., Ltd.: PEG2000, polyethylene glycol PEG400, Na2SO3, NaOH, pentaerythritol, caprolactone, sulfuric acid, thionyl chloride, sodium carboxymethylcellulose, N-methylpyrrolidone, decaglycerol, triethylene glycol, methyl methacrylate, dibenzoyl peroxide, acrylamide, butyl acrylate, p-styrenesulfonic acid, chlorosulfonic acid, trimesic acid, hexamethylenediamine, pyromellitic acid, 2,4-diaminobenzenesulfonic acid, etc.

[0113] LiNi 0.8 Co 0.1 Mn 0.1 O2 comes from Hubei Yongbai Lithium Battery Materials Co., Ltd. The conductive agent (Super P® Li) and PVDF adhesive (Solef® 5130) are from SOLVAY (SHANGHAI) Co., Ltd. The artificial graphite comes from Tianjin Beitrui New Energy Technology Co., Ltd. Styrene butadiene rubber latex (SBR) (solid content 50%), alumina powder, polyethylene porous film, lithium hexafluorophosphate, ethylene carbonate (EC), ethyl methyl carbonate (EMC), and vinylene carbonate were sourced from Shanghai McKinney Biochemical Technology Co., Ltd.

[0114] The present invention will be described in more detail below using examples and comparative examples, but the technical scope of the present invention is not limited to these examples. As a matter of explanation, unless otherwise specified, all percentages, parts, and ratios used in the present invention are by weight. Examples of the preparation of various ionic polymers are described below.

[0115] Polyether Production Example 1 Add 760g of decaglycerol (1mol), 200g of LiOH aqueous solution (concentration 10wt%) and 1000g of water into the reactor, stir thoroughly at room temperature to dissolve, add 640g of acrylonitrile (AN, 12mol), the molar ratio of decaglycerol to AN is 1:12, react at 40℃ for 20 hours, then raise the temperature to 90℃ and reflux for 9 hours, a large amount of basic gas is generated, collect it with acidic aqueous solution, add the remaining 2680g of LiOH aqueous solution to neutralize, the total molar ratio of LiOH to AN added twice is 1:1, after the reaction is completed, vacuum dry and obtain lithium carboxyl-containing polyether 1, the structural formula of which is shown below:

[0116] [ka]

[0117] Polyether Production Example 2 Add 1000g of polyethylene glycol PEG2000 (0.5mol), 1g of Mg(OH)2 and 1500g of water into a reactor, stir thoroughly at room temperature to dissolve, add 53g of acrylonitrile (AN, 1mol), the molar ratio of PEG2000 to AN is 1:2, react at 40℃ for 20h, then heat to 90℃ and reflux for 9h, a large amount of basic gas is generated, collect with acidic aqueous solution, add PEG2000 and equimolar amount of magnesium carbonate (0.5mol, 42g) to neutralize, dissolve while reacting, after reaction is completed, dry under vacuum to obtain polyether 2 containing magnesium carboxylate groups, the structural formula of which is shown below:

[0118] [ka]

[0119] Polyether Production Example 3 At 80°C, 40g of polyethylene glycol PEG400 (0.1mol) was slowly added with 23.8g of thionyl chloride (0.2mol). The molar ratio of PEG400 to thionyl chloride was 1:2. A large amount of gas was generated. The gas was neutralized by adding NaOH aqueous solution. After reacting for 18 hours, the reaction solution was cooled to room temperature and added dropwise to 250g of Na2SO3 aqueous solution (10wt%). The molar ratio of PEG400 to Na2SO3 was 1:2. After the addition was completed, the reaction was continued for 5 hours at 65°C. The product was dissolved in acetonitrile, the unreacted inorganic salts were removed, and the mixture was dried under vacuum to obtain polyether 3 containing sodium sulfonate groups. The structural formula is shown below.

[0120] [ka]

[0121] Polyether Production Example 4 50g of polyethylene glycol PEG (M n =5000, 0.01 mol) was dissolved in an NMP solution, and then 2.44 g of 1,3-propane sultone PS (0.02 mol) was added to the NMP solution of polyethylene glycol, with a molar ratio of PEG to PS of 1:2. The reaction was carried out at 40°C for 24 hours, and an equivalent amount of LiOH aqueous solution (10 wt%) to the PS was further added to neutralize the mixture. The NMP solvent and water were removed, and the mixture was dried under vacuum to obtain polyether 4 containing lithium sulfonate groups, with the structural formula shown below.

[0122] [ka]

[0123] Polyether Production Example 5 Add 300g triethylene glycol (2mol), 15g LiOH aqueous solution (10wt%) and 500g water into a reactor, stir well at room temperature to dissolve, add 212g acrylonitrile (AN, 4mol), the molar ratio of triethylene glycol to AN is 1:2, react at 40℃ for 20 hours, then heat to 90℃ and reflux for 9 hours, a large amount of basic gas is generated, collect with acidic aqueous solution, add 945g LiOH aqueous solution to neutralize, after the reaction is completed, vacuum dry and obtain polyether 5 containing carboxylic acid lithium group, the structural formula is as follows:

[0124] [ka]

[0125] Polyether Production Example 6 Under nitrogen gas protection, 60g of dried polyethylene glycol PEG600 (0.1mol) was added to an NMP solution of 23.3g of chlorosulfonic acid (0.2mol), the molar ratio of PEG600 to chlorosulfonic acid was 1:2, and the mixture was stirred at 100°C to react, generating a large amount of gas. The gas was neutralized by adding an aqueous NaOH solution. After reacting for 18 hours, the reaction solution was cooled to room temperature and added dropwise to 48g of an aqueous LiOH solution (10wt%), the molar ratio of PEG600 to LiOH was 1:2. The NMP solvent and water were removed, and the mixture was dried under vacuum to obtain polyether 6 containing lithium sulfate groups, the structural formula of which is shown below.

[0126] [ka]

[0127] Polyester Production Example 1 Add 495g of oxalic acid (5.5mol) and 310g of ethylene glycol (5mol) to the reactor, the molar ratio of oxalic acid to ethylene glycol is 1.1:1, add 3g of p-toluenesulfonic acid as a catalyst, evacuate, react at 160℃ for 10 hours, add acetonitrile to dissolve after stopping the reaction, add LiOH aqueous solution to adjust the pH to 7.0, evacuate and dry, the final product is polyester 1 containing lithium carboxylate groups, the structural formula is as follows:

[0128] [ka]

[0129] Polyester Production Example 2 A reaction vessel was charged with 13.6 g of dried pentaerythritol (0.1 mol) and 183 g of caprolactone monomer (1.6 mol). 150 g of N,N-dimethylformamide (DMF) solvent and 0.6 g of sulfuric acid catalyst were then added. The reaction was allowed to proceed for 24 hours at 110°C. After quenching, the reaction was continued for sulfonation. 48 g of thionyl chloride (0.4 mol) was slowly added dropwise to the polymer solution at 80°C. A large amount of gas evolved, which was neutralized by adding an aqueous NaOH solution. After 18 hours of reaction, the reaction solution was cooled to room temperature and added dropwise to 504 g of a 10 wt% aqueous NaSO solution. After the addition was complete, the reaction was allowed to proceed for 5 hours at 65°C. Unreacted inorganic salts were removed and the mixture was dried under vacuum. The final product, a star-shaped polyester 2 containing sodium sulfonate groups, had the following structural formula:

[0130] [ka]

[0131] Polyolefin Production Example 1 16.4g of azobisisobutyronitrile (AIBN, 0.1mol), 1500g of polyethylene glycol methyl ether methacrylate (MPEGMA300, 5mol), and 311g of 2-acrylamido-2-methylpropanesulfonic acid (AMPS, 1.5mol) were added to a reactor, with the molar ratio of AIBN, MPEGMA300, and AMPS being 1:50:15. 1.5kg of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 70°C under nitrogen gas protection for 10 hours. The reaction was stopped, and an aqueous LiOH solution was added until the pH was adjusted to 7.0. The reaction was then dried under vacuum to obtain polyolefin 1 containing lithium sulfonate groups, with the structural formula shown below.

[0132] [ka]

[0133] Polyolefin Production Example 2 32.8g of azobisisobutyronitrile (AIBN, 0.2mol), 636g of acrylonitrile (AN, 12mol), 400g of methyl methacrylate (MMA, 4mol), and 344g of methacrylic acid (MAA, 4mol) were added to a reactor, with the molar ratio of AIBN, AN, MMA, and MAA being 1:60:20:20. 1.2kg of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 70°C under nitrogen gas protection for 10 hours. The reaction was stopped, and an aqueous LiOH solution was added until the pH was adjusted to 7.0. The reaction was then dried under vacuum to obtain polyolefin 2 containing lithium carboxylate groups, with the structural formula shown below.

[0134] [ka]

[0135] Polyolefin Production Example 3 2.42g of dibenzoyl peroxide (BPO, 0.01mol), 852g of acrylamide (AM, 12mol), 2304g of butyl acrylate (BA, 18mol), and 1830g of p-styrenesulfonic acid (SSA, 10mol) were added to a reactor, with the molar ratio of BPO, AM, BA, and SSA being 1:1200:1800:1000. 4kg of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 80°C under nitrogen gas protection for 10 hours. The reaction was stopped, and an aqueous LiOH solution was added until the pH was adjusted to 7.0. The reaction was then dried under vacuum to obtain polyolefin 3 containing lithium sulfonate groups, with the structural formula shown below.

[0136] [ka]

[0137] Polyolefin Production Example 4 4.84g of dibenzoyl peroxide (BPO, 0.02mol), 198g of methyl acrylate (MA, 2.3mol), 173g of vinyl sulfonic acid (SVA, 1.6mol), and 22.8g of 2-hydroxyethyl methacrylate phosphate (HEMAP, 0.1mol) were added to a reactor, with the molar ratio of BPO, MA, SVA, and HEMAP being 1:115:80:5. 600g of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 80°C under nitrogen gas protection for 10 hours. The reaction was stopped, and an aqueous LiOH solution was added until the pH was adjusted to 7.0. The mixture was then dried under vacuum to obtain polyolefin 4 containing lithium sulfonate groups, with the structural formula shown below.

[0138] [ka]

[0139] Polycarbonate production example 1 Add 6.2g of dried ethylene glycol (0.1mol) and 204g of propylene carbonate monomer (2mol) into the reactor, the molar ratio of ethylene glycol to propylene carbonate is 1:20, add 100g of solvent N,N-dimethylformamide (DMF) and 0.5g of catalyst stannous octoate, react at 90℃ and nitrogen gas protection for 12 hours, stop the reaction, cool to 0℃, add 23.3g of chlorosulfonic acid HSO3Cl (0.2mol), the molar ratio of chlorosulfonic acid to ethylene glycol is 2:1, react overnight, add appropriate amount of LiOH aqueous solution until pH is adjusted to 7.0, vacuum dry, obtain polycarbonate 1 containing lithium sulfate group, the structural formula is as follows:

[0140] [ka]

[0141] Polycarbonate production example 2 Add 31g of dried ethylene glycol (0.5mol) and 264g of ethylene carbonate monomer (3mol) to the reactor, the molar ratio of ethylene glycol to ethylene carbonate is 1:6, add 130g of solvent N,N-dimethylformamide (DMF) and 7.5g of catalyst stannous octoate, react at 90℃ and nitrogen gas protection for 12 hours, stop the reaction, cool to 0℃, add 116.5g of chlorosulfonic acid HSO3Cl (1mol), the molar ratio of chlorosulfonic acid to ethylene glycol is 2:1, react overnight, add appropriate amount of LiOH aqueous solution until pH is adjusted to 7.0, vacuum dry, obtain polycarbonate 2 containing lithium sulfate groups, the structural formula is as follows:

[0142] [ka]

[0143] Polyamide Production Example 1 212.2g of dried trimesic acid (1.01mol) and 116.2g of hexamethylenediamine (1mol) were added to a reactor, and the molar ratio of trimesic acid to hexamethylenediamine was 1.01:1. The reaction was carried out at 250℃ under vacuum for 12 hours. After the reaction was stopped, water was added to dissolve the mixture, and at the same time, an aqueous LiOH solution was added until the pH reached 7.0. The mixture was then dried under vacuum. The final product obtained after drying was polyamide 1 containing lithium carboxyl groups, and its structural formula is as follows:

[0144] [ka]

[0145] Polyamide Production Example 2 Add 513.4g of dried pyromellitic acid (2.02mol) and 120g of ethylenediamine (2mol) into reactor, the molar ratio of pyromellitic acid to ethylenediamine is 1.01:1, react under the condition of 250℃ and vacuum for 12 hours, after stopping the reaction, add water to dissolve, and at the same time add LiOH aqueous solution until pH is adjusted to 7.0, then vacuum dry, the final product obtained after drying is polyamide 2 containing lithium carboxyl group, and its structural formula is as follows:

[0146] [ka]

[0147] Polyamide Production Example 3 Add 295.2g of dried adipic acid (2.02mol) and 376.4g of 2,4-diaminobenzenesulfonic acid (2mol) into the reactor, the molar ratio of adipic acid to 2,4-diaminobenzenesulfonic acid is 1.01:1, react for 12 hours under vacuum at 250℃, add water to dissolve after the reaction is stopped, add LiOH aqueous solution until the pH is adjusted to 7.0, then vacuum dry, the final product obtained after drying is polyamide 3 containing lithium sulfonate and lithium carboxyl groups, the structural formula is as follows:

[0148] [ka]

[0149] The performance of the ionic polymers was tested using the following methods, and the results are shown in Table 1. (1) Measurement of molecular weight of ionic polymer: The absolute molecular weight of the ionic polymer was measured by gel permeation chromatography-laser light scattering (GPC-MALLS), the gel permeation chromatograph was a 1515 GPC gel permeation chromatograph from Waters, USA, and the light scattering detector was a DAWN HELEOS-II light scattering detector from Wyatt, USA.

[0150] (2) The ratio of the ionic polymer mass to the number of moles of anionic groups contained therein (M a ) Measurement: First, metal cations in the ionic polymer, such as Li, were analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES). + , Na + , Mg 2+ , Al 3+The concentrations of these compounds were tested. The specific test method is as follows: 1.0 g of sample was accurately weighed into a 50 mL PTFE beaker, 3 mL of concentrated nitric acid and 9 mL of hydrochloric acid were added, and the sample was heated at 150°C for 30 minutes in a graphite digestion furnace. The sample was then transferred by filtration into a 100 mL measuring flask and tested using an ICP-OES. The ICP-OES model used was a PQ9000 from Jena Analytical Instruments, Germany.

[0151] Furthermore, the ratio of the ionic polymer mass to the number of moles of anionic groups contained therein (g / mol) M a was calculated.

[0152]

number

[0153] In the above formula, C i is the concentration of metal cations in the polymer measured by ICP-OES, in g / kg, and M i is the relative atomic mass of the corresponding metal cation, and n i is the valence of the metal cation, e.g., Li + and Na + So n i is 1 and Mg 2+ and Ca 2+ Then the corresponding n i is 2 and Al 3+ Then the corresponding n i is 3.

[0154] (3) Measurement of swelling degree: An ionic polymer film was cut into a 30 μm thick, 16 mm x 16 mm circular film sheet. The film sheet was weighed, immersed in 10 g of electrolyte, sealed, and stored at 60°C. Every 8 hours, the film sheet was removed, the electrolyte on the surface was wiped off, the thickness was measured, the weight was measured, the film was returned to the electrolyte, sealed, and stored at 60°C until the thickness and mass of the film sheet remained unchanged after three consecutive tests. The ionic polymer film sheet was considered to have reached swelling equilibrium. The swelling degree was calculated according to the following formula: the difference in mass before and after immersion in electrolyte divided by the mass of the film sheet before immersion × 100%.

[0155]

number

[0156] In the above formula, m0 represents the mass of the ionic polymer film sheet before immersion in the electrolyte, and m1 represents the mass of the ionic polymer film sheet when it reaches swelling equilibrium after immersion in the electrolyte. The electrolyte was prepared as follows: In a glove box with a dew point below -40°C, lithium hexafluorophosphate (LiPF6) was dissolved in a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (volume ratio of EC to EMC: 3:7) to prepare an electrolyte with a LiPF6 concentration of 1.2 mol / L. Vinylene carbonate (VC) and 1,3-propane sultone (1,3-PS) were then added, accounting for 1.5% and 1% of the total weight of the electrolyte, respectively, to obtain the desired electrolyte.

[0157] (4) Measurement of swelling loss rate The ionic polymer was cut into a circular film sheet measuring 30 μm in thickness and 16 mm x 16 mm in size. The mass of the film sheet was weighed, immersed in 10 g of electrolyte, sealed, and stored at 60°C. Every 8 hours, the film sheet was removed, the electrolyte on the surface was wiped off, the thickness was measured, the weight was measured, the sheet was returned to the electrolyte, sealed, and stored at 60°C until the thickness and mass of the film sheet remained unchanged after three consecutive tests. The remaining electrolyte and lithium salt were washed off with dimethyl carbonate (DMC), and the sheet was placed in a drying box and completely dried. The mass of the film sheet remaining after drying was weighed, and the swelling loss rate was calculated using the following formula:

[0158]

number

[0159] In the above formula, m0 represents the mass of the ionic polymer film sheet before immersion in the electrolyte solution, and its unit is g, and m2 represents the mass of the ionic polymer film sheet remaining after immersion in the electrolyte solution, further washing, and drying, and its unit is g. The electrolyte was prepared as follows: In a glove box with a dew point below -40°C, lithium hexafluorophosphate (LiPF6) was dissolved in a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (volume ratio of EC to EMC: 3:7) to prepare an electrolyte with a LiPF6 concentration of 1.2 mol / L. Vinylene carbonate (VC) and 1,3-propane sultone (1,3-PS) were then added, accounting for 1.5% and 1% of the total weight of the electrolyte, respectively, to obtain the desired electrolyte.

[0160] Example 1 1. Battery manufacturing 1.1 Positive plate manufacturing LiNi, the positive electrode active material 0.8 Co 0.1 Mn 0.1O2, carbon black conductive agent (Super P® Li), and PVDF adhesive (Solef® 5130) were mixed in a weight ratio of 96.5:1.5:2 and placed in a double planetary mixer. The total weight of the positive electrode active material, carbon black conductive agent, and adhesive was 1 kg. 0.5 kg of N-methylpyrrolidone (NMP) was added and stirred thoroughly and uniformly. After that, polyester 1, accounting for 2% of the total weight of the solids of the positive electrode material, was added. After further stirring, the mixture was filtered to obtain a positive electrode material slurry with a solids content of 65%. The slurry was then applied to both sides of a 12 μm-thick aluminum foil using an extrusion coater. After baking and hot rolling, a positive electrode plate was obtained. The areal density of the coating on one side of the positive electrode plate was 20 mg / cm. 2 The thickness of the single-sided coating was 58 μm.

[0161] 1.2 Negative plate manufacturing The negative electrode active materials, artificial graphite, carbon black conductive agent (Super P® Li), and sodium carboxymethylcellulose (CMC) were mixed in a weight ratio of 97:1.5:1.5 and then placed in a double planetary mixer. The total weight of the negative electrode active material, carbon black conductive agent, and sodium carboxymethylcellulose was 1 kg. 0.8 kg of deionized water (DIW) was added and thoroughly and uniformly stirred. After thorough and uniform stirring, 50% styrene butadiene rubber latex (SBR) and 4% polyether 1 were added. The mixture was further stirred uniformly and filtered to obtain a negative electrode material slurry with a solids content of 45%. The slurry was then applied to both sides of 6 μm-thick copper foil using an extrusion coater. After baking and hot-rolling, a negative electrode plate was obtained. The areal density of the coating on one side of the negative electrode plate was 13 mg / cm. 2 The thickness of the single-sided coating was 79 μm.

[0162] 1.3 Separator manufacturing Alumina powder (D50 = 1.5 μm) and sodium carboxymethylcellulose (CMC) were mixed in a weight ratio of 99.25:0.75 and then added to 1.5 kg of deionized water (DIW). The total weight of the alumina powder and sodium carboxymethylcellulose (CMC) was 1 kg. The mixture was stirred and ground in a mixer grinder until the alumina particle size was 2 μm or less. The mixture was then transferred to a mixing jar. A 50% solids styrene-butadiene rubber latex (SBR) and a 4% solids polyether 2 mixture were added. The mixture was stirred uniformly and then filtered to obtain a separator coating material slurry with a solids content of 10%. The slurry was then gravure-printed onto one surface of a 9 μm-thick polyethylene porous film (45% porosity). This process was repeated to coat the other surface of the polyethylene porous film. After drying, a composite porous separator with a single-sided inorganic coating thickness of 3 μm was obtained, and the total thickness of the composite porous separator was 15 μm.

[0163] 1.4 Dry battery cell manufacturing The positive electrode plate, the negative electrode plate, and the separator were cut into shapes such that the size of the active material region of the positive electrode plate was 48 mm × 44 mm, the size of the active material region of the negative electrode plate was 52 mm × 46 mm, and the size of the separator was 56 mm × 50 mm, and such that current collector lead portions remained on each of the positive electrode plate and the negative electrode plate. Next, they were stacked in the order of negative electrode plate, separator, positive electrode plate, separator, negative electrode plate, ... so that a total of 18 positive electrode plates and 19 negative electrode plates constituted the outermost layers. Next, the current collector lead portions of the positive electrode plates were welded with an ultrasonic welding machine, and positive electrode tabs were welded, and the current collector lead portions of the negative electrode plates were welded with an ultrasonic welding machine, and negative electrode tabs were welded, thereby obtaining a stack.

[0164] The laminate was placed in a packaging bag made of two punched aluminum-plastic films, the hot melt adhesive on the tab was welded to the packaging bag using hot melt, and the tab was pulled out of the packaging bag, leaving an air bag and a liquid injection port on one side of the packaging bag, thereby obtaining a dry battery cell.

[0165] 1.5 Electrolyte Production In a glove box with a dew point below -40°C, lithium hexafluorophosphate (LiPF6) was dissolved in a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (volume ratio of EC to EMC: 3:7) to prepare an electrolyte solution with a LiPF6 concentration of 1.2 mol / L. Vinylene carbonate (VC) accounting for 1.5% of the total weight of the electrolyte solution and 1,3-propane sultone (1,3-PS) accounting for 1% were further added to obtain the desired electrolyte solution.

[0166] 1.6 Battery manufacturing The above electrolyte was injected into the dry battery cell through the liquid inlet in a glove box with a dew point below -40°C, and after leaving it to stand for 24 hours, the liquid inlet on the outside of the airbag was sealed with a vacuum heat seal, and at the same time, the gas inside the battery cell was removed, thus obtaining an unformed battery cell. The weight of the unformed battery cell was measured, and the weight of the dry battery cell was subtracted to obtain the weight of the injected electrolyte.

[0167] 1.7 Battery formation The battery cell was subjected to chemical formation using a charge / discharge device, first by constant current charging at a current of 0.05 C to 3.6 V, then by evacuating using a vacuum heat seal, venting, sealing the opening, and cutting off the air bag, then by constant current charging at a current of 0.2 C to 4.2 V, further by constant voltage charging until the current decreased to 0.05 C, and then by constant current discharging at a current of 0.2 C to 3.0 V, to obtain a chemically formed battery cell, i.e., a gel electrolyte lithium-ion battery according to the present invention.

[0168] 2. Battery testing 2.1 First discharge capacity test The batteries formed at room temperature were charged at a constant current of 1 C to 4.2 V, then charged at a constant voltage until the current decreased to 0.05 C, and then discharged at a constant current of 1 C to 3.0 V to obtain the initial discharge capacity (Ah). Next, some of the batteries were subjected to a high-temperature storage test, and some of the batteries were subjected to a charge-discharge cycle test.

[0169] 2.2 High-temperature storage test At room temperature, the battery was charged at a constant current of 1 C to 4.2 V, and then charged at a constant voltage until the current decreased to 0.05 C. The battery was then transferred to a dry box at 60°C and stored for 7 days. The battery was then taken out and its thickness was measured. The thickness expansion rate was calculated by comparing it with the thickness before high-temperature storage, i.e., thickness expansion rate = (battery thickness after high-temperature storage - battery thickness before high-temperature storage) / battery thickness before high-temperature storage × 100%.

[0170] After the battery was cooled to room temperature, it was discharged at a constant current of 1 C to 3.0 V, and the obtained discharge capacity was compared with the discharge capacity before high-temperature storage to calculate the capacity retention rate, i.e., capacity retention rate = discharge capacity after high-temperature storage / discharge capacity before high-temperature storage × 100%.

[0171] Next, the battery was charged at a constant current of 1 C up to 4.2 V, then charged at a constant voltage until the current decreased to 0.05 C, and then discharged at a constant current of 1 C down to 3.0 V. The resulting discharge capacity was compared with the discharge capacity before high-temperature storage to calculate the capacity recovery rate, i.e., capacity recovery rate = discharge capacity after recharge / discharge after high-temperature storage / discharge capacity before high-temperature storage × 100%.

[0172] 2.3 Charge-discharge cycle test The battery was charged at room temperature at a constant current of 1 C to 4.2 V, then charged at a constant voltage until the current decreased to 0.05 C, and then discharged at a constant current of 1 C to 3.0 V. After 1000 cycles, the final discharge capacity was compared with the initial discharge capacity to calculate the discharge capacity retention rate.

[0173] 2.4 Nail penetration test The battery nail penetration safety test was conducted in accordance with GB / T31485-2015, in which a steel pin with a diameter of 8 mm was used to pierce the battery in a direction perpendicular to the plate at a speed of 25 mm / s and then fixed in the battery, and the battery was observed for 1 hour. The test results are shown in Table 2.

[0174] Example 2 The manufacturing process for the positive plate was the same as in Example 1, except that 3% polyolefin 2 (instead of 2% polyester 1) was added to the manufacturing process for the positive plate, 5% polyether 5 (instead of 4% polyether 1) was added to the manufacturing process for the negative plate, and 8% polyether 3 (instead of 4% polyether 2) was added to the manufacturing process for the separator. The test was carried out according to the test method for the battery of Example 1, and the test results are shown in Table 2.

[0175] Example 3 The manufacturing process for the positive plate was the same as in Example 1, except that 2.5% polyamide 1 (instead of 2% polyester 1) was added to the manufacturing process for the negative plate, 4% polyamide 2 (instead of 4% polyether 1) was added to the manufacturing process for the negative plate, and 50% polyolefin 1 (instead of 4% polyether 2) was added to the manufacturing process for the separator. The test was carried out according to the test method for the battery of Example 1, and the test results are shown in Table 2.

[0176] Example 4 The manufacturing process for the positive plate was the same as in Example 1, except that 1% Polyester 2 (instead of 2% Polyester 1) was added to the manufacturing process for the negative plate, 1% Polyolefin 1 (instead of 4% Polyether 1) was added to the manufacturing process for the negative plate, and 1% Polyether 6 (instead of 4% Polyether 2) was added to the manufacturing process for the separator. The test was carried out according to the test method for the battery of Example 1, and the test results are shown in Table 2.

[0177] Example 5 The manufacturing process for the positive plate was the same as in Example 1, except that 10% polycarbonate 1 (instead of 2% polyester 1) was added to the manufacturing process for the negative plate, 10% polyolefin 1 (instead of 4% polyether 1) was added to the manufacturing process for the negative plate, and 80% polyolefin 4 (instead of 4% polyether 2) was added to the manufacturing process for the separator. The test was carried out according to the test method for the battery of Example 1, and the test results are shown in Table 2.

[0178] Example 6 The manufacturing process for the positive plate was the same as that of Example 1, except that 3% polyolefin 3 (instead of 2% polyester 1) was added to the manufacturing process for the negative plate, 5% polyamide 3 (instead of 4% polyether 1) was added to the manufacturing process for the separator, and no ionic polymer was added to the manufacturing process for the separator. The test was carried out according to the test method for the battery of Example 1, and the test results are shown in Table 2.

[0179] Example 7 The process was the same as Example 1, except that 5% Polycarbonate 2 (instead of 2% Polyester 1) was added to the manufacturing process of the positive plate, and no ionic polymer was added to the manufacturing process of the negative plate and separator. The test was carried out according to the test method for the battery of Example 1, and the test results are shown in Table 2.

[0180] Example 8 The manufacturing process of the negative electrode plate was the same as that of Example 1, except that 8% polyether 5 (instead of 4% polyether 1) was added to the manufacturing process of the negative electrode plate, 20% polyether 2 (instead of 4% polyether 2) was added to the manufacturing process of the separator, and no ionic polymer was added to the manufacturing process of the negative electrode plate. The test was carried out according to the test method for the battery of Example 1, and the test results are shown in Table 2.

[0181] Example 9 The process was the same as Example 1, except that 5% polyamide 2 (instead of 4% polyether 1) was added to the negative plate manufacturing process, and no ionic polymer was added to the positive plate and separator manufacturing processes. The test was carried out according to the test method for the battery of Example 1, and the test results are shown in Table 2.

[0182] Example 10 The manufacturing process was the same as Example 1, except that 60% Polyolefin 1 (instead of 4% Polyether 2) was added to the separator manufacturing process, and no ionic polymer was added to the positive and negative plate manufacturing processes. The test was carried out according to the test method for the battery of Example 1, and the test results are shown in Table 2.

[0183] Comparative Example 1 The manufacturing process for the positive electrode plate, the negative electrode plate, and the separator was the same as in Example 1, except that no ionic polymer was added. The test was carried out according to the test method for the battery of Example 1, and the test results are shown in Table 2.

[0184] Comparative Example 2 The process was the same as Example 1, except that 5% Polyether 4 (instead of 4% Polyether 1) was added to the negative plate manufacturing process, and no ionic polymer was added to the positive plate and separator manufacturing processes. The test was carried out according to the test method for the battery of Example 1, and the test results are shown in Table 2.

[0185] Comparative Example 3 The manufacturing process for the positive plate was the same as in Example 1, except that 0.5% of Polycarbonate 2 (instead of 2% of Polyester 1) was added to the manufacturing process for the negative plate, 0.5% of Polyolefin 1 (instead of 4% of Polyether 1) was added to the manufacturing process for the negative plate, and 0.5% of Polyether 3 (instead of 4% of Polyether 2) was added to the manufacturing process for the separator. The test was carried out according to the test method for the battery of Example 1, and the test results are shown in Table 2.

[0186] Comparative Example 4 The manufacturing process for the positive plate was the same as in Example 1, except that 15% polycarbonate 2 (instead of 2% polyester 1) was added to the manufacturing process for the negative plate, 15% polyolefin 1 (instead of 4% polyether 1) was added to the manufacturing process for the negative plate, and 15% polyether 3 (instead of 4% polyether 2) was added to the manufacturing process for the separator. The test was carried out according to the test method for the battery of Example 1, and the test results are shown in Table 2.

[0187] [Table 1]

[0188] [Table 2]

[0189] As can be seen from Table 1, the M of the ionic polymers used in Examples 1 to 10 w / M a The swelling loss ratios were all less than 5% and the swelling degree of the ionic polymer in the electrolyte at 60°C was 55 to 250%, all of which were greater than 50%.

[0190] As can be seen from Table 2, in Examples 1 to 10, the lithium-ion batteries obtained by adding the ionic polymer of the present invention to the electrode or separator coating material had a high-temperature storage thickness expansion rate of 2.9 to 4.3%, a high-temperature storage capacity retention rate of 90.3 to 92.4%, a high-temperature storage capacity recovery rate of 93.5 to 95.8%, and a room-temperature cycle capacity retention rate of 92.5 to 93.8% after 1000 cycles. The nail penetration test results showed that none of the batteries ignited or exploded. In Comparative Example 1, the ionic polymer of the present invention was not added to either the electrode or separator. In Comparative Example 2, an ionic polymer soluble in the electrolyte was added to the negative electrode plate. In Comparative Example 3, less than 1% of the ionic polymer was added to both the electrode and separator. The high-temperature storage performance of these batteries was lower than that of Example 1, and no fires occurred in the nail penetration test. On the other hand, in Comparative Example 4, the electrode contained more than 10% ionic polymer, and the battery did not ignite or explode in the nail penetration test, but the battery performance dropped sharply during cycling. Therefore, the lithium ion battery obtained by adding the ionic polymer of the present invention to the electrode material or separator coating material clearly had improved high-temperature storage performance and safety.

[0191] In summary, the present invention adds an ionic polymer to a positive electrode, a negative electrode, or a separator, and after contacting the ionic polymer with an electrolyte, the ionic polymer absorbs the electrolyte and swells to form a gel electrolyte. This reuses the conventional production process and avoids the problems of the prior art caused by adding a gel polymer or its precursor to the electrolyte, such as a complicated process, an unstable electrolyte, and difficulty in infiltrating into electrodes, and meets the requirements for high energy density batteries. At the same time, the use of a gel electrolyte instead of a liquid electrolyte reduces electrolyte leakage, solvent volatilization, and contact between the electrolyte and the surface of the active material, thereby improving the high-temperature cycle performance and safety of the battery, extending the service life of the battery, and reducing the risk of battery fire or explosion, and has extremely wide application prospects.

[0192] Although the present application has been disclosed above by the preferred embodiments, it is not intended to limit the scope of the claims, and those skilled in the art can make some possible changes and modifications without departing from the spirit of the present application, and therefore the scope of the claims of the present application shall conform to the scope defined by the claims of the present application. The above description is only the preferred embodiments implemented in the present invention, and is not intended to limit the present invention in any way, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A gel electrolyte lithium ion battery comprising an ionic polymer, The battery includes a positive electrode, a negative electrode, a separator, and an electrolyte, wherein at least one of the positive electrode, the negative electrode, or the separator includes an ionic polymer, and M in the ionic polymer w / M a is between 2 and 2000, where M w is the weight average molecular weight of the ionic polymer, M a is the ratio of the mass of the ionic polymer to the number of moles of anionic groups contained therein, and M a is 100 to 2000 g / mol, A gel electrolyte lithium-ion battery.

2. M in the ionic polymer w / M a 2. The gel electrolyte lithium ion battery according to claim 1, wherein the ρ is 2 to 1000, preferably 2 to 500.

3. Said M a 3. The gel electrolyte lithium ion battery according to claim 1, wherein the ionic strength is 100 to 1000 g / mol.

4. the swelling degree of the ionic polymer in the electrolyte solution is greater than 50%, preferably the swelling loss of the ionic polymer in the electrolyte solution is <5%, more preferably the swelling degree is 50-500% at 25-60°C; 4. The gel electrolyte lithium ion battery according to claim 1, wherein the gel electrolyte lithium ion battery is a lithium ion battery.

5. the positive electrode includes a current collector and a positive electrode material applied to the current collector, preferably the positive electrode material includes a positive electrode active material and an ionic polymer, more preferably the content of the ionic polymer is 1 to 10% based on the total weight of the solid content of the positive electrode material; and / or the negative electrode includes a current collector and a negative electrode material coated on the current collector, preferably the negative electrode material includes a negative electrode active material and an ionic polymer, more preferably the content of the ionic polymer is 1 to 10% based on the total weight of the solid content of the negative electrode material; and / or the separator comprises a polymer microporous layer and a separator coating material applied to the polymer microporous layer, preferably the separator coating material comprises inorganic particles and an ionic polymer, and more preferably the content of the ionic polymer is 1 to 80% based on the total weight of the solid content of the separator coating material.

6. The anion group of the ionic polymer is one or more selected from a carboxylate ion, a sulfonate ion, a sulfate ion, and a phosphate ion, and preferably the cation of the ionic polymer is one or more selected from a lithium ion, a sodium ion, a magnesium ion, a calcium ion, a barium ion, and an aluminum ion.

6. The gel electrolyte lithium ion battery according to claim 1, wherein the gel electrolyte lithium ion battery is a lithium ion battery.

7. 7. The gel electrolyte lithium-ion battery according to claim 1, wherein the ionic polymer is one or more polymers selected from the group consisting of polyethers containing at least two anionic groups, polyesters containing at least two anionic groups, polyolefins containing at least two anionic groups, polycarbonates containing at least two anionic groups, and polyamides containing at least two anionic groups.

8. The ionic polymer is one or more polymers selected from the following: 【Chemistry 1】 where R 1 ~R 3 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X 1 ~X 3 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group, and X 1 ~X 3 at least one of is an ionic group containing an anionic group and a cation, and m and n are both integers of 1 to 5000; 【Chemistry 2】 where R 4 ~R 6 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X 4 ~X 6 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group, and X 4 ~X 6 at least one of is an ionic group containing an anionic group and a cation, and m and n are both integers of 1 to 5000; 【Transformation 3】 where R 7 ~R 11 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X 7 ~X 10 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group, and X 7 ~X 10 at least one of is an ionic group containing an anionic group and a cation, and n is an integer of 1 to 5000; 【Chemistry 4】 where R 12 ~R 17 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X 11 ~X 14 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group, and X 11 ~X 14 at least one of is an ionic group containing an anionic group and a cation, and l, m, and n are all integers of 1 to 5000; 【Transformation 5】 where R 18 ~R 20 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X 15 ~X 17 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group, and X 15 ~X 17 at least one of is an ionic group containing an anionic group and a cation, and m and n are both integers of 1 to 5000; 【Transformation 6】 where R 21 ~R 23 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X 18 ~X 20 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group, and X 18 ~X 20 at least one of is an ionic group containing an anionic group and a cation, and m and n are both integers of 1 to 5000; 【Transformation 7】 where R 24 ~R 28 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, or a sulfur-containing substituted hydrocarbon group; X 21 ~X 25 are each independently selected from hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing substituted hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, a phosphorus-containing substituted hydrocarbon group, a sulfur-containing substituted hydrocarbon group, or an ionic group, and X 21 ~X 25 8. The gel electrolyte lithium ion battery according to claim 7, wherein at least one of the groups is an ionic group containing an anionic group and a cation, and n is an integer of 1 to 5000.

9. The polyolefin containing at least two anionic groups in the polymer side chain is formed by copolymerization of an olefinic monomer containing an ionic group and an olefinic monomer not containing an ionic group, and the structural formula of the olefinic monomer containing an ionic group is as shown below: 【Transformation 8】 where R 1 , R 2 , R 3 are each independently selected from a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, an oxygen-containing substituted hydrocarbon group, or a halogen-containing substituted hydrocarbon group; R 4 is selected from a hydrocarbon group, a nitrogen-containing substituted hydrocarbon group, an oxygen-containing substituted hydrocarbon group, or a halogen-containing substituted hydrocarbon group, and X is an ionic group containing an anionic group and a cation.

10. 10. The gel electrolyte lithium ion battery of claim 9, wherein the olefinic monomer not containing an ionic group comprises one or more of styrene, methylstyrene, acrylonitrile, acrylate, methacrylate, acrylamide, N-substituted methacrylamide, vinyl ether, N-vinylpyrrolidone, vinylpyridine, maleic anhydride, maleimide, vinylene carbonate, and vinylethylene carbonate.

11. the electrolytic solution contains an organic solvent and a lithium salt, and preferably, the organic solvent is one or more selected from ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, and methyl propyl carbonate; More preferably, the lithium salt is one or more selected from the group consisting of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium di(trifluoromethylsulfonyl)imide, and lithium bisfluorosulfonylimide, and is preferably lithium hexafluorophosphate.

12. the electrolytic solution further contains one or more of an unsaturated cyclic carbonate, a fluorinated cyclic carbonate, a cyclic sultone, and a cyclic sulfate; Preferably, the unsaturated cyclic carbonate is selected from vinylene carbonate and / or vinyl ethylene carbonate, and / or the fluorinated cyclic carbonate is at least one selected from fluoroethylene carbonate, trifluoromethylethylene carbonate, and bisfluoroethylene carbonate, and / or the cyclic sultone is at least one selected from 1,3-propane sultone, 1,4-butane sultone, and propenyl-1,3-sultone, and / or the cyclic sulfate ester is at least one selected from vinyl sulfate, propylene sulfate, and 4-methyl vinyl sulfate.

13. A method for producing a gel electrolyte lithium ion battery according to any one of claims 1 to 12, The method includes the steps of forming a positive electrode, a negative electrode, and a separator into a battery cell, placing the battery cell in a battery case, injecting an electrolyte solution into the battery case to obtain a semi-finished lithium ion battery, forming the semi-finished lithium ion battery, and then evacuating the battery and sealing the liquid inlet of the battery case to obtain a gel electrolyte lithium ion battery.

14. 1. A lithium ion battery electrode, comprising: a current collector and an electrode material coating applied to the current collector, wherein the electrode material coating is w / M a ionic polymers and active materials, wherein M is 2 to 2000; w is the weight average molecular weight of the ionic polymer, M a is the ratio of the mass of the ionic polymer to the number of moles of anionic groups contained therein, and M a is 100 to 2000 g / mol, Preferably, the amount of the ionic polymer added is 1 to 10% based on the total weight of the solid content of the electrode material, and more preferably, the electrode is a positive electrode or a negative electrode.

15. 1. A lithium ion battery separator, comprising: a polymeric microporous layer and a separator coating material applied to the polymeric microporous layer, wherein the separator coating material comprises inorganic particles and an ionic polymer, and M in the ionic polymer. w / M a is between 2 and 2000, where M w is the weight average molecular weight of the ionic polymer, M a is the ratio of the mass of the ionic polymer to the number of moles of anionic groups contained therein, and M a is 100 to 2000 g / mol, Preferably, the amount of the ionic polymer added is 1 to 80% based on the total weight of the solid content of the separator coating material, and more preferably, the polymer microporous layer is a polyolefin microporous film or nonwoven fabric.

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